Generally, monitoring power usage at one or more locations (for example, residential, building, commercial and industrial sites) for billing purpose may involve calculating a power rate by measuring the power usage (i.e., power consumption) at the one or more locations. A utility meter (i.e., electricity meter, power meter, or the like) is a well-known device employed (and managed by utility agencies) for measuring the power usage. In addition to the utility meter, the deployment of a submeter at the one or more locations is increasing rapidly in order to monitor the power consumption of individuals (such as tenants, property owners, or the like) located therein. The submeter can facilitate the individuals to measure the power consumed by the individual equipment(s) and monitor the power usage accordingly thereto communicating the information to agencies managing the submeter. Each individual can, therefore, use the power usage measurements communicated from the submeter for effectively monitoring the bill as per the usage levels.
According to the constructional feature, measurement points of each utility meter and the submeter may be interfaced (passed) through a transformer. The power usage measured at the utility meter may include all measurement values measured at a high-voltage (HV) terminal after transformation (i.e., from the transformer) and the power usage measured at the submeter may include all measurement values measured at a low-voltage (LV) terminal after transformation. As the efficiency (i.e., ratio of the output (LV) to input (HV)) of the transformer is not ideal, a difference may occur between both the measurement points passing through the transformer. As a result, an error occurs due to difference in the measurement value of the power usage.
Furthermore, a minimum unit time between measurement and marking of power usage of the utility meter is 15 minutes. A minimum unit time between measurement and aggregation of power usage of the submeter may be 1 second or less. Also, there may be a time discrepancy (102), as shown in FIG. 1, between a measurement time and a marking time of the utility meter (for example, a power usage (104) marked between time instances 10:00 and 10:15 may actually be the power usage of the utility meter measured between time instances 9:57 and 10:12), as shown in the FIG. 1. Therefore, comparing the power usage measurement between the time instances 10:00 and 10:15, (which is measured by the submeter) and the power usage measurement between the time instances 10:00 and 10:15 (which is measured by the utility meter) is as equivalent to that of comparing power usages of different periods.
Thus, there exists a mismatch in the power usage measurement of the utility meter and the power usage measurement of the submeter (marked and measured at the same time instances 10:00 and 10:15 to that of the utility meter).
Thus, it is desired to address the above mentioned error caused due to the mismatch of the power usage measurements between the utility meter and the submeter or other shortcomings or at least provide a useful alternative.